1. Field of the Invention
The present invention relates to a container for storing a biological sample. More particularly, the present invention relates to a container for storing a biological tissue specimen in a reagent or, if so desired, in multiple reagents for molecular or diagnostic testing and/or histological testing.
2. Description of Related Art
Biological samples are often obtained by a researcher or clinician for diagnostic evaluation to determine the presence of certain diseases and to determine an appropriate treatment for the disease. Tissue samples are often obtained from a patient for molecular diagnostic and nucleic acid analysis, particularly RNA and DNA analysis, which have become common place in research for the treatment of numerous diseases. An essential requirement for accurate RNA and DNA analysis is the presence of high quality and intact RNA and DNA within the biological sample.
Oftentimes, the histologic or cytologic analysis will be performed immediately after the sample is removed from the patient or source to avoid molecular changes that may occur during storage. These changes, such as gene transcription, result from the degradation of the nucleic acids within the sample caused by exposure of an untreated sample to certain environmental stresses. However, analysis of the sample immediately after the sample is collected is often impossible or impractical. Therefore, it is necessary to provide a system for storing a sample under controlled conditions for a certain period of time while maintaining the structural and molecular integrity of the sample.
Traditionally, one way of accomplishing this storage is by submerging the sample in a single fixative reagent. A typical fixative reagent is 10% formalin but may also include water, miscible alcohols, ethanol/acetone mixtures, and ethanol/acetic acid mixtures. The containers used for such storage are generally composed of a single integral cavity which could house an effective volume of reagent to treat a particular biological tissue sample. The biological tissue sample is placed in the container along with the reagent, the container is closed, and the sample is then stored and transported while being preserved by the fixative agent. An example of such a container can be seen in U.S. Pat. No. 7,147,826 to Haywood et al. Such containers have experienced some success in the industry, but are subject to certain limitations.